The present disclosure relates to a switch device for an on-board power supply, and an on-board power supply system.
JP 2015-83404A discloses an on-board power supply device. This on-board power supply device includes a main battery, a sub-battery, first to third switches, a first auxiliary device group, and a second auxiliary device group. The first to third switches are connected to each other in series in this order between the main battery and the sub-battery. The first auxiliary device group is connected to a point between the first switch and the second switch via a first wire. Accordingly, when the first switch is turned on, the first auxiliary device group receives a supply of power from the main battery. Also, when the second switch and the third switch are turned on, the first auxiliary device group also receives a supply of power from the sub-battery. The first auxiliary device group may be, for example, an audio system, a safety device, a car navigation system, or an ECU for controlling idling stop.
The second auxiliary device group is connected directly to the main battery via a second wire, and is connected to a point between the second switch and the third switch via a third wire. Accordingly, the second auxiliary device group receives a supply of power directly from the main battery, and also receives a supply of power from the sub-battery when the third switch is turned on. The second auxiliary device group may be an electronically-controlled brake system, a vehicle wireless communication system, or the like.
Also, a technique related to the present disclosure is disclosed in JP 119-233694A.